Filter for air conditioning apparatus



Feb. 26, 1957 w. G. SPIEGELHALTER 2,732,612

FILTER Non AIR CONDITIONING APPARATUS Filed Dec. 5. 1955 FIGJ vse' a7 3o 3' 27 HINT 2O 62 59 2' INVENToR. 5? WlLLlAM G. SPlEGELHALTR B HIS ATTORNEY United States Patent FmTER FoR AIR coispmoNlNG ApPARATUS l s William G. Spiegelhalter, Erie, Pa., assignor to General Electric Company, a corporationof New York Application member s, 195s, sei-tn No.' 555,093

4 claims. (ci. sz-129) v Filteringof air to bevconditionedhas in the past been vusually accomplished by a thin, porous slab of filtering material located in the air duct of the air conditioning apparatus.

It can be seen that after the filter has been in operation for an ex'- tended period, it` must be removed from the apparatus and either cleaned or discarded. Cleaning a filter is usually a time consuming and expensive operation and to discard the filterbefore its useful life has expired additionally increases the cost.

Accordingly it is an object of my invention to provide a new and improved arrangement for filtering the air circulated through air conditioning apparatus prior to its discharge into the enclosure to be conditioned.

A further object of my invention is to provide an improved inexpensive, self-replacing, filtering` arrangement for an air conditioning unit in which the used `filtering surfaces are automatically replaced according to the number of on-ol operations of the apparatus.

A still further object of my invention is to provide a novel, self-replacing, air filter for air conditioning apparatus which is automatically shifted to replace the used filtering surfaces. 'A

It is still another object of my invention to `provide an improved, self-replacing air 'lter for air conditioning apparatus which is provided with its own replacement filter surfaces and which discontinues the operation of the apparatus when additional replacement surfaces are no longer available.

It is another object of my invention to provide a filtering arrangement for an air conditioning unit which is simple in construction, inexpensive, and ecient in operation and which may be used over long periods of unit operation before a new filtering arrangement need be substituted.

In carrying out my invention, I provide an air conditioning unit for conditioning the air within an enclosure which is provided with a refrigeration system including an evaporator or chilling unit over which air is circulated so that it may be cooled before being discharged into the enclosure. In order to llter the air moved over the evaporator, I provide a continuous filter which is arranged adjacent the evaporator in such a manner that successive portions of the filter can be presented to the circulating air for filtering purposes as the previously presented filter portions become used. I also preferably provide means Patented Feb. ze, 1951 ige . Y 2 q to index the movementof the lter past-the evaporator in accordance Vwith the number of times the unit is operated. When all of the filtering surfaces are exhausted, the unit operationv is discontinued through switching means arranged to detect the need for a completely new continuous filter. v

The'novel features which I believe-to be characteristic of my invention are set forth with particularity in the appended claims. My invention, however, both asto itsb organization and method of operation may be best understood byreference to the following description taken in conjunction with the accompanying drawing in which:

Fig. 1 is a vertical sectional view of an air conditioning unit including my invention; Fig. 2 is a partialhorizolital view taken substantially along line 2 2 of Fig. l; and

Fig. 3v is a schematic diagram of an electrical circuit adaptedforuse with the air conditioning apparatus of Fig. l. v

Referring now to Fig. 2, I have shown therein a selfcontained room air conditioner adapted for mounting in a window of the room to be conditioned. The air conditionei includes a section 1 projecting into the room The air is moved'through this lter slab which removes the entrained dust and lint.

and an outer section 2 which extends outside the room preferably into the outside atmosphere. Between the two sections 1 and 2, I position a partition 3 which divides my .unit into an indoor and an outdoor compartment as defined by sections 1 and 2 respectively. I also provide an external gasket 4 around the unit at the point where my partition 3 is located to 'prevent leakage of outside air into the room. The indoor section 1 is preferably provided with a screened opening S through which con- -ditioned air is discharged into the room and the outdoor section 2 is provided with Vopenings (not shown) which permit the: outside air to be drawn into the outdoor section and discharged back into the atmosphere. As is conventional in this type of air conditioning apparatus, some damper arrangement may be providedwhereby a portion or all of the outside air may be conducted into the room for Ventilating or mixing. This damper arrangement is preferably located so as to cooperate with the baille 3. It will be noted that I have only'partially shown the outdoor section 2 of my airconditioner in Fig. 2 and it should be understood that it may be of any suitable design usually found in air conditioners of this type wherein outside air. is circulated through the outdoor section.

My air conditioning unit alsoincludes ya conventional mechanical refrigeration' system having an evaporator 6, a compressor 7 and a condenser (not shown). Both the compressorv and condenser are -of the conventional type common to air conditioning apparatus and are suitably located within the air conditioner preferably in that portion of the air conditioner through which the outside air is circulated. As will be understood the compressor 7 and condenser are suitably connected in refrigerant flow circuit. In order to simplify the drawing, the interconnecting conduits between the components have been omitted.

During the operation o f my air conditioner, room air is drawn intothe indoor section l and moved over the evaporator coil 6 which extracts heat from the air cooling it. The cooled air is then discharged into the room.

In section 2 of the air conditioner, wherein are. preferably located the condensing unit and the compressor 7 of section the evaporator 6 of the refrigeration system. The air conditioner may if desired be provided with a removable top wall 8 which is suitably received along its lower edge by a formed portion 9 extending along the top edge of the two sections 1, 2. This basic arrangement is illustratve of the type of air conditioners to which my invention may be'adapted. More specifically, my invention deals with the construction of the compartment of the indoor section and the arrangement'for supplying cool, cleaned air to the room to beconditioned. However, the embodimentr of my inventionyshown herein appurtenant to the indoor section of the air conditioner, is not necessarily so limited and may if desired be associated with the outdoor section or with both sections.

Referring now to Fig. 1, the indoor section l is provided with partitioning means 10 extending horizontally acrossthe lower portion of section l and dividing section l into two sub-compartments l1 and l2. The partition 10 has a rectangular portion removed as shown in Fig. 2 to provide an opening 13.

In order to circulate the room air through section 1 of my air conditioner, I provide an opening 14 in the bottom wall l5 of section l. The opening 14 communicates with the axial intake of air moving means such as a centrifugal fan 16 arranged for rotation about a vertical axis within atcasing 17. The fan 16 is driven by lmeans of a belt 18 suitably connected. by means such as pulleys 19, 20 to an electric motor 21. The motor 21 is suitably mounted as shown in Fig. l on the bottom wall of section l within the lower compartment 11. The fan motor may be energized as desired by separate switching means (not shown) or may be energized simultaneously with the operation of the air conditioner.

but some provisions should be made for continuously cleaning it, or if outside air isbroughtrinto the room through the unit it must likewise be cleaned. I have therefore provided a filtering arrangement for use with my air conditioner which consists of a rolled-up strip of filtering material which may be unrolled and simultaneously rolled onto another roller as new filtering surface is needed. My filtering arrangement is therefore located in the path of the circulating room air prior to its discharge into the room to be conditioned.

More specifically, I position a pair of substantially vertical roller shafts'27, 28 within section l, as shown in Fig. 1, which are laterally arranged on opposite sides of the evaporator 6 and disposed parallel to the surface of the tins 26. The shaft 27 isl suitably mounted and 4is freely rotatably within bearing support 29 arranged on partition10. The upper end of the roller shaft-27 extends through an aperture in the top wall 8 of the unit"v` and terminates in a manual operating knob 3l. Appropriate means are provided (not shown) to maintain the shaft in the vertical'position. Roller shaft 28 also has an upper end extending through an aperture 32 in the -top wall 8 and terminates in a knob 33. This shaft 28 by suitable means which are not shown.

is also appropriately maintained in the vertical position The lower end of roller shaft 28 extends through an aperture 34 in partition 10 and tenninates in a bevel'pinion gear 35. The pinion forms a part of my filter shaft driving mechanism located in compartment 11 of section 1.

IThus the roller shaft 27 is arranged to be frerly rotatable in its bearing support 29 and the roller shaft 28 is Although I have preferably shown a blower 16 driven used instead of a centrifugal blower and the motor 21 may be mounted elsewhere within my air conditioner. For instance, the motor 21 may be directly connected to the blower or fan instead of a belt drive and may be used simultaneously for driving the air moving means for the outside air. l

Referring now to Fig. 2, the air drawn in through opening 14 by the fan 16 moves through a-plenum chamber 22 having an enlarged open end 23 arranged within the compartment 11. As can be seen, the plenum charnber 22 is arranged as an extensionof the fan casing 17. The open end of the chamber 23 is of the same dimensions and is in sealing relationship 'with the opening 13 in the partition 10 so as to communicate therewith.

As previously discussed, I have preferably located the evaporator 6 of my refrigeration system within indoor opening 5 in the front wall 26 of section l. My evaporator 6 may be positioned by any suitable mounting means (not shown) and is connected as discussed above within my closed refrigeration system by appropriate tubing. With this arrangement, air which is moved over the evaporator 6 where it is cooled by the refrigerant flowing through the coil 24 of the evporator may then subsequently pass through the discharge opening 5 in the unit front wall 26 and into the room to be conditioned.

' The air within the enclosure or room generally acquires a considerable amount of entrained dust, dirt, or lint in everyday living and if this air is to be satisfactorily conditioned it is not suticient to provide for cooling it arranged to be rotatably driven by its bevel pinion 35.

Referring now to Fig. 2, my filtering arrangement for the room air which is drawn into the indoor section 1 of my air conditioner'and circulated over the evaporator 6 consists of an elongatedrtape .or strip 36 of filtering material, such as porous paper, which is initially'wound on the freely rotatably shaft 27 as shownin Fig. 2. -The filter strip 36 is then partially unwound -from theshaft 27 and its free end is passed around a plurality of vertical support rods 37 suitably mounted on the partition 10 in compartment 12 of'section 1. Then its free end is attached by any convenient means to the driven roller shaft 28. For instance, the shaft 28\may be provided with a radial slot4 into which the free end of the strip 36 is inserted and then wound around the shaft to secure it in place.

Thus it will be seen in my preferred arrangement that the strip of filtering material 36 lies on the upstream side of evaporator 6 and room air beforelmoving over the evaporator passes trst through the filtering strip which cleans it before being discharged through opening 5 in the front wall 26 of section l. Although I have preferably shown my filtering strip 36 located on the upstream side of the evaporator6, it may also be located if desired on the downstream side without effecting the operation of my invention.

In order that the circulated air does not pass around the filter strip 36 and out the discharge opening 5 without being cleaned, I provide baes 38 and 39 as shown in Fig. 2 which extend up to the point adjacent the tlter strip where the strip enters and leaves the plane of the support rod 37 respectively. The bales 38, 39 are suitably mounted on the interior of the end walls of section 1. Thus all the air which is moved towards the evaporator 6 must pass first through the filtering strip 36 as the baffles 38, 39 substantially seal the passages around the strip.

With the roll of filtering material on the roller shaft 27, a supply of fresh filtering material is readily available and may be rolled off the freely rotatable shaft 27 when the driven toller shaft 28 is rotated. In order to roll off a fresh portion of filtering strip, I therefore provide a driving mechanism for the roller shaft 28 which is actuated when my air conditioning unit is actuated to the "on position. By moving the iilter strip tion by'rotation of the control knob 54, switch arm56 with the unit starting mechanism, I obtain automatically is moved into engagement with contact 59. Switch 60 a replacement of the used iilterstrip portion. More at Vthis time is also closed as shown in Fig. 3 by the specically, I provide a bevel gear 39 as shown in Fig. venlarged diameter of the strip 36 on shaft 27 compressl which meshes with the bevel pinion on the lower 5 ing the switch arin`-61 against contact 62. Thus a comend of the driven rollershaft 28. As shown in Fig.2, plete circuit is established and the motor of compressor the-bevel' gear 39 isrxedly mounted within the com- 7 is energized by supply conductors 57 and 58 to inipartment 11 on a freely rotatable shaft 40 supported tiate the operation'of-the refrigeration system. I have at one 'end by suitable journaling means such as boss preferablyrshown'v in Fig. 3 the fan motor 21 in parallel 41 on the forward wall 26 of section 1. The shaft 40 10 with the compressor motor in the circuit and it is there is supported at its other end' by a bracket 42 suitably f fore simultaneously energized by conductors 57, 58 when attached to 'the bottom wall 15'ot` section l. c switchesv 55 and 60 are closed. l The fan 16 therefore In order to rotatably drive the shaft and its xed rotates to draw Vroom air through opening 14 in the bevel gear 39, a toothed ratchet 43 is also xedly secured bottom wall l5 of section 1 where it passes through the to the shaft 40 adjacent the gear 39. The ratchet 43 15 plenum chamber 22 arranged in'compartment 11 to be contains peripherally spaced teeth 44 which lare arranged 'subsequently discharged l.through opening 13 in partition toengage an opposing row of horizontally spaced -teeth 10 and into compartment 12. As the bathe 3 and asso- 45 on a rack 46 as shown in Fig. l. This rack 46 is eiated damper means, if provisions for bringing in outarranged for reciprocal movement and its forward end Side air are provided, seal section 1 from the `outer secis loosely positioned in a slot 47 provided in a bracket 20 tion 2 of the air conditioner and as partitions 38 and 48 suitably secured such as by screws to the bottom wall 39 are arranged adjacent the end portions of the filter l5 of section 1. The opposite end of the rack'46I is strip 36, the circulating air moves in the direction of loosely pinned to a link 49 which is iixedly secured to the alrOWS tllrougl1 ille filler Strip 36 and Over the eVaP- control rod 50. I have provided a spring 5 1 connected orator 6 where it is both cleaned by the iilter and cooled at one end to rack 46 and at the other end to link 49. 25 by the transfer of its heat to the evaporator 6. The ait'v As can be seen in Fig. l, the spring 51 resists any pivotthen moves back into the room to be cooled through the able movement which increases the angle between the dSCllal'ge Opening 5 in tlle fl'Ont Wall 26 0f the unit.

link and rack, When the unit is to be de-activated, the control knob 54 The conti-o1 rod 50 is supported for rotatable moveis rotated in a counterclockwise direction rotating the ment within an upstanding bracket 52 suitably secured -30 control rod 50 and link 49 to slide the rack 46 to' the right` as by screws to the bottom wall 15 of section l. The 0r toward the fan motor 21 as viewed in Fig. I. The tooth rod extends at itS forward end through an aperture 0n rack 46 which is in engagement with the corresponding 53 in the forward wall 26 of section l below the partione of the teeth 44 on the ratchet 43 moves into engagetion 10 and terminates in a control knob 54 as Shown ment with the adjacent ratchet tooth during this movement in Fig. 2. Rotation of control rod 50 by means of knob 35 of the rack to the right. When the unit is once again ac- 54 functions to control the operation of the air contivated by a clockwise rotation of the knob 54, link 49 roditioner 0f my invention as appropriato controls conlateS with the .COIltl'Ol I'Od 50 again Sliding the rack 46 vcntional to this type of air' conditioning unit are con. Y to the left as viewed in Fig. l, against the holding action nected to the control `rod 50. One such control switch,` 0f SPYing 5l'- AS CDII'eSPOndng teeth on the rack 46 and connected to the rod 50 ismy unit starting switch 55 40 ratchet 43 are in engagement there is a resulting rotation shown in Fig. 2 suitably supported on the rear of the m a clockwise direction of the ratchet 43 as the rack nnit front wall 26, slides. It will be understood that the end of the rack 46 Referring now Vto Fig, 3, I have Shown the Switch arm slides freely within the slot 47 of bracket 48 as the slot 56 of the operation control Switch 55 by which the motor oters no resistance to the movement of the rack. Rotaof compressor 7 in rny refrigeration system may be oper. 45 tion of the ratchet 43 consequently rotates the pinion gear ated by connecting the compressor motor 'across a pair 39 through the shaft 40. As the gear 39 is meshed with of supply conductors 57vand 5s The switch arm 55 i, bevel pinion gear 35 on the driven roller shaft 28, the

connected to the control rod 50 as discussed above so shaft 28 is likewise rotated in the direction shown 4by thev that rotation of the control knob 54 in a clockwise dir-oo. arrow in Fig. 2. Rotation of shaft 28 winds a portion of tion from that of the position of Fig, 1 will mov'o the 5o the filter strip 36 onto t-he roller 28 and unwinds a portion switch arrn 56 into contact making engagement with of the same length from the roller Vshaft 27. Thus it will contact 59, The closing of switch arm 56 howeveronly Lebe understood that each time the unit is activated and departially Connects the motor of compressor 7 into thc aCllVaed a Sed pOl'llOIl 0f the l'lllel Slllp 36 S WOlllld OIl circuit with the supply. conductors 57, 58, ag I have Shaft 28 and a fresh portion of the same length is rolled provided another Switching means 50 Shown in Fig 2 55 off the roller 27. The length of strip moved during each between the compressor motor and the power supply. fPefallOn Qf tlle Unit may be 0f any desired length. aeCOl'd- The'switch 60 is suitably supported on the roar of thc Y lng to the operating conditions of the air conditioner and unit front wall 26 adjacent the roller shaft 27'and conmay be determined by the arrangement 0f lhe driving tains a movable contact arm 61. The switch 60 is in mechanism A circuit closing position when the lilter strip 36 is wound 60 I' have thus found that the Useful life 0f the ltef SUP onto roller shaft 27 and the Strip roll diameter large is proportional to the number of on-off operations of the enough to hold the switch arm 61 into cil-cuit closing air conditioner and an average number. of on-oti opera engagement with a contact 62, tions of the unit over a period of time will continuously 1n the operation of my invention, the filter strip 35 h present a fresh portion of lter material to the circulating is wound Omo roller Shaft 27 and its free end is pulled 65 air to insure that the' circulated room air is continuously across the rear of the evaporator 6 and the rods 37. being Properly lred I The strip end is then attached to the rod 23 and a few Referring now to Fig. 2, in order to automatically sense turns of the shaft 23 are made with the knob to par, when the iilter strip 36 is completely unwound from the tiauy Wind the strip end on the Sha/L The operating roller shaft 27 and wound onto roller shaft 28 necessitatknobs3l and 33 may also be manually rotated in order 70 mg the replacement with a new filter roll my feder to draw the lter strip 36 tightly between the two shafts Switch arm 61 which is gradually moving towards the 27, 28 as shown in Fig. 2. Thus a fresh strip of filter dotted line position of Fig. 2 as the filter roll is used material is now interposed between the circulating air eventually dis-engages from the Contact 52 thus Opening andthe rear of the evaporator. the circuit to the motor of compressor 7 and fan 21. When the air conditioner is switched to the on posi- Thus the unit is de-activated and the operator cannot surfaces is accomplishedl and the need for frequent manual lter'changes no longer arises. Furthermore the replacement of used filter surfaces with unused filter surfaces is accomplished in a simple manner automatically in an arrangement where the number of times the unit is operf ated determines the amount of lter surface that-is .replaced. In addition, the driving arrangement for replac-` ing the used filter surfaces is simple in operation since, through the provision of the linkage between the filter driving arrangement and the air conditioner switching means, the operator automatically moves the filter strip when the unit is activated.

While in accordance with theppatents statutes, I have de'- scribed what at present is considered to be the preferred embodiment of my invention, 'it will be understood to those skilled in the art that various changes and modifications may be made therein without departing from my invention, and I, therefore, aim in the appended Vclaims to cover all such changes and modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters 'Patent of the United states is:

l. Air conditioning apparatus for an enclosure oom- I prising a refrigeration system including an evaporator,

A portion of said strip each time said apparatus is activated,

and means to de-activate said apparatus when said last filter portion has been presented toA said circulatv3. Air conditioning apparatus for an enclosure coma refrigeration system including an evaporator, means to circulate air over said evaporator and into said enclosure, said evaporator arranged in a plane substantially perpendicular to said air ow, a rpair of upstanding rotatable shafts arranged at opposite ends of said evaporator, one of said shafts being freely rotatable, a lter for sard circulating air comprising a flexible strip wound on said freely rotatable shaft, said strip arranged to be simultaneously unwound from said freely rotatable shaft and wound on'said other shaft parallel to said evaporator surface sov as to present successive unused portions to said air, indexing means to drive said other shaft so as to present uniform 'successive unused strip portions, said indexing means arranged to move a portion of said strip each time said apparatus is activated, and

switch means responsive. to the diameter of the filter roll on one of said shafts to de-activate said apparatus when said last unused filter portion has been presented' to said circulating air. 1

4. Air conditioning apparatus for an enclosure comprising a refrigeration system including an evaporator, means to circulate air over said evaporator and into said enclosure, said evaporator arranged in a plane substan-v tiaily perpendicular to said air' flow, a pair of upstanding rotatable shafts arranged at opposite ends of said evaporator, one of said shafts being' freely rotatable, a filter means to circulate air over said evaporator andinto said enclosure, a ilter comprising a exible strip associated in part with said evaporator for filtering saidV circulatingY air, said filter strip movable adjacent said evaporator so vas to present successive unused portions to said circulating air, and indexing means for moving said filter strip so as to present uniform successive` unused portions of said strip to said circulating air, said indexing means acting to move a portion of said strip each time said apparatus is activated.

2. Air conditioning apparatus for an'enclosure comprising a refrigeration system including an evaporator, means to circulate air over said evaporator and into said enclosure, a filter comprising a exible strip associated in part with said evaporator for filtering said circulating'air,

said strip movable adjacent lsaid-evaporator so as to'pre' sent successive unused portions to said circulating air, and indexing means for moving said strip so as to present uniform successive unused portions of said strip to said for said circulating air comprising a flexible strip wound on said freely rotatable shaft, said strip arranged to be a'multaneously unwound from said freely rotatable shaft and wound on said other s haft parallel to said evaporator surface so as to present successive unused portions to said circulating air, indexing'means to drive said other shaft so as -to present uniform successive unused strip porcirculating air, said indexing means acting to move-a p tions, switch means for activating said air. conditioning apparatus, said indexing means arranged to move a portion of said strip each time said apparatus switch means are moved to the activating position, and switch means responsive to the diameter of said filter roll on one of said shafts to de-'aetivate said apparatus when said last unused filter portionhas been presented to said circulating air.

References Cited the filel of this patent UNITED STATES PATENTS v 1,822,471 Borden Sept. 18, 1931 .I 2,495,002 Hart Jan. 17, 1950 2,626,012 Persons c Ian. 20, 1953 

